I don't think anyone has actually argued that the series is intentionally anti-semitic.
"Intent doesn't matter, impact does."
I don't know if there's any one person I can attribute this idea to, but I've seen it thrown around a lot. But that aside...
However, the characterisation of goblins builds on a lot of traditional anti-semitic caricatures.
Generally, if you're going to depict a secretive cabal of greedy bankers who control the economy and only trust their own kind, you're probably referencing (consciously or otherwise) traditional anti-semitic ideas about Jews. That's why, if you need to do this for some reason, don't give them hooked noses.
A lot of this is stretching things.
Quick, I say "goblin," and what are some traits that come to mind? Love of gold, and hooked noses. This isn't something that's limited to Harry Potter, this is a common goblin trope, period. Also, there's no evidence that the goblins actually run the economy, but semantics.
What I want to know is who the heck read Harry Potter, came across the goblins, and thought, "Jews!" I mean, obviously they exist, but seriously?
Again, I don't think anyone has actually argued that the series actually promotes chattel slavery. However, it does depict a world in which slavery is, for the most part, a benevolent and functional institution, where the only issues stem from rare and individual incidents of mistreatment, where the enslaved races are fiercely loyal and naturally suited to slavery and where abolitionism is viewed as naive and silly.
Firstly, that's a bit weird. Secondly, it clearly draws (knowingly or otherwise) upon actual, real life anti-abolitionist arguments.
That's really only half the story.
The house elf 'thing' comes in two stages. In Book 4, Hermione founds SPEW, and the plotline doesn't really go anywhere. Like, there isn't some house elf rebellion. In Book 5 though, it's touched on again, via Dumbledore's "the statue told a lie" comments. We know later on that Hermione does try to ensure house elf welfare when she becomes minister of magic.
Point being with the house elves, it looks at it from both perspectives. On the one hand, she's ignorant, because she's imposing her own views on a different species that has different goals and desires. On the other, the (potential) abuse of the house elves is acknowledged, and that goes beyond Dobby and Winky. But the idea of house elves being in a state of 'benevolent slavery' really doesn't seem to hold up. This isn't the first time in the series where Hermione's established to have a trait of being narrow minded, for better or worse.
Secondly, the series doesn't really reject the concept of blood purity. It depicts a world where the capacity for magic is hereditary, where magical bloodlines exist and where marriage between wizards is very clearly the traditional norm. Everyone within this setting is aware of these facts. What is rejected within the books is overt mistreatment of others on the basis of blood purity.
Magic's hereditary, but you either have magic or you don't. There's no shades of ability linked to 'blood purity.' If there was, Malfoy, for instance, should be among the most powerful of students, and Voldemort shouldn't be nearly as powerful as he is. Also, the whole marriage thing? It's outright stated more than once that there's very few pure-blood families left in the Wizarding World.
The issue is less the number of POC characters, and more the fact that the POC characters who do exist tend to be irrelevant and often represent obnoxious or reductive stereotypes. Cho Chang, for example, beyond having a name which sounds like a racist joke about Chinese names, is a character whose only function in the story is to date people, be a love interest and be a weak character so that the real love interest appears stronger by comparison. POC characters are generally treated like scenery, rather than being fully fleshed out characters.
TBH, I can't think of a single ethnic stereotype within the series. National stereotype, sure, but ethnic? No.
For one thing, I don't think the books spend that much time actually describing character ethnicity. I remember when the films came out, and many characters were cast in a way I didn't imagine them to be. Obviously stereotypes/archtypes exist, but the racial side? Not so much. And if we're talking about Cho Chang specifically, what in her character is stereotypical? That she's in Ravenclaw and East Asians tend to excel in academia?
Also, I disagree that's Cho's function, and even if it was, did it even work? HarryxGinny isn't that popular from what I can tell. Certainly ChoxHarry is my preferred pairing, but I've never been into shipping that much, at least in this particular setting.
People always knew it was about AIDS. It's not exactly subtle.
The problem is that we have two prominent werewolf characters. One is a sympathetic heterosexual who is unfairly persecuted, and the other is a monster who preys on children and tries to infect them and turn them against their parents.
You cannot claim to be exploring the issue of HIV prejudice while also having a character who represents the absolute worst excesses of HIV prejudice and anti-gay hysteria.
People always knew it was about AIDS...since when? Certainly not when the books came out. I don't recall when I stumbled across the idea, but it flagergasted me that people thought it was a metaphor for AIDS. Yes, Rowling came out later and said it was (in 2016), over a decade since lycanthropy was introduced to the series. But people criticized lycanthropy when it wasn't a metaphor for AIDS, and now people are criticizing it when it IS a metaphor for AIDS. Here's me wondering how many of these people actually understand that lycanthropy as a fictional concept pre-dates AIDS by quite awhile.
Also, beyond Dumbledore's retroactive gayness, reading him as gay is not hugely flattering. He's an eccentric old man whose only experience of romantic love was a tragic infatuation with a heterosexual who didn't return his affections. If Dumbledore was gay, then he never found a satisfying or loving relationship, or a community which accepted him for who he was, and he died lonely and celibate. The troubling implication of Rowling declaring that she always imagined Dumbledore as gay is that it suggests she views gay lives as inherently tragic and lonely.
I thought Grindlewald was established to return Dumbledore's affections. Certainly Crimes of Grindlewald indicates it.
As for Dumbledore being gay, again, I think this is a case of Rowling digging a hole for herself. On the other hand...well, that interpretation isn't without a foundation to stand on, but dying lonely and celibate isn't limited to Dumbledore in the series. Take Snape for example.
Some of these do seem pretty made up, or at least distorted far beyond the intent of the original point being made.
I can easily make up points of criticism for HP, but every one of those points I listed was a point that I've seen someone bring up. It's technically possible that they were made up points, but I really can't be sure. Not in this day and age. FFS, this very site had an article saying that Gears 5 was a "celebration of genocide." It was the article that got me to sign up for a Disqus account because I couldn't believe that anyone could come to that conclusion. The same principle applies to all media. Yeah, no media is free from critique, but some of the critiques are just bizzare. But I don't doubt that people actually believe them in most cases.
